Artificial limb



G. E. BECK RTIFICIAL LIMB July 9, 1940.

Filed Nov. 26, 1957 ?4 26 V Inventor 76 Gdfi erfiZ. 59 an" Attorneys Patented July 9, 1940 UNITED STATES.

ARTIFICIAL Gilbert E. Beck, Andrade, Calif.

Application November 26, 1937, Serial No. 176,743

1 Claim.

My invention relates to improvements in artificial legs, the primary purpose of the invention being to provide a light weight device of this character embodying a water and dust-proof foot and ankle assembly constructed and arranged to provide for a maximum degree of articulative movement and with a minimum amount of friction between the parts.

Another object is to provide in a device of the character and for the purpose above set forth improved means for attaching the foot and ankle assembly to the leg shank so as to form a waterproof and dust-proof joint therebetween.

Still another object is to provide an articulated resilient foot and ankle assembly which will not wrinkle or become deformed at the joint.

To the accomplishment of the above, and subordinate objects presently appearing, a preferred embodiment of my invention has been illustrated in the accompanying drawing, set forth in detail in the succeeding description and defined in the claim appended hereto.

In said drawing:

Figure 1 is a view in vertical section of an artificial leg embodying my improvements,

Figure 2 is a view partly in front elevation and partly in vertical section of the foot and ankle joint,

Figure 3 is a view in side elevation of said joint, I

Figure 4 is a similar view of an eye bolt and roller bearing assembly forming part of said joint,

Figure 5 is a detail view in elevation of the eye bolt.

Describing the invention in detail, with reference to the drawing by numerals, l designates the leg shank which is hollow, as usual, and may be formed of any suitable light, strong material.

The foot and ankle assembly of my invention comprises an ankle block 2, of suitable hard wood, rabbeted around its upper edge, as at 3, to fit into the lower end of the shank l and to which it is secured preferably by glue, not shown. Below the ankle block 2, and spaced therefrom, is a foot block 4 of light, strong material, preferably cypress wood, and intermediate said blocks 2 and 4 is a cushion member 5 of sponge rubber. The foot block 4 is secured to the ankle block 2 by means of a joint designated, as a unit, by the 50 numeral 6 and comprising the following: An eyebolt 1 is extended upwardly through the ankle block 2, centrally thereof, and secured'in said block by means of the usual nuts 8 threaded onto the upper end thereof, one nut being a locking device as will be understood. The head 9 of the eye-bolt 1 extends part way into a socket Ill formed in the lower side of the ankle block 2 and is equipped with an upper lateral flange ll bearing against the bottom of said socket I0. Secured to the top of the foot block 4, as presently de- 5 scribed, and centrally thereof is a yoke l2 comprising a base plate l3 having a pair of lateral spaced, apertured, upstanding ears I4 thereon extending through a suitable aperture I5 in the cushion member 5 and between which the head 9 10 of eye-bolt l is loosely fitted and secured thereto by a pintle l6 of hard steel and having its ends fitted into the apertures of said ears. A dowel pin l1 extending through one ear l4 and said pintle l6 secures the latter in position. As will 16 be understood the axis of the described joint is horizontal and transverse to the plane of the ankle and foot blocks 2 and 4. Fitted into the head 9 of the eye-bolt l is a roller bearing assembly comprising an outer race member l8 ex- 20 tending at its sides beyond the sides of said head, and roller bearings 59 running in said race member and on the pintle I6. A pair of washers 20 are fitted onto the extending sides of the race member. l8. Another pair of washers 2| are provided on the pintle i6 between opposite sides of the described bearing assembly and said ears I 4 respectively. The yoke I2 is secured to the foot block 4 by countersinking the base plate l3 thereon in a socket 22 formed in the upper side of said block and by bolts 23 extending through said block 4 and also through a clamping plate 24 fitted into a socket 25 formed in the underside of said block 4 for accommodating the ends of said bolts 23 and nuts 26 threaded onto said ends. 3

The blocks 2 and 4, and the cushion member 5 are provided with a covering 21 forming the foot and ankle proper and extending to the shank l with a feathered edge preferably overlapping the lower end of the latter. The cover 21 is made of liquid rubber brushed, or dipped, on by coats and of a composition which is self-vulcanizing. Preferably the composition such 'as' is known commercially as Airvule is used for this purpose which possesses properties obviating wrinkling and buckling under flexing. As will be understood the covering 21 seals the entire ankle and foot assembly including the joint 6 and the juncture of the ankle with the shank I.

At the top of the shank l is a stump socket comprising a cufi 28 the loweredge of which is rabbeted externally as at 29 and fitted in a corresponding internal rabbet 30 in the top edge of said shank. The part designated 4! is the knee joint 10 ther explanation.

Manifestly the invention, as described, is susceptible of modification without departing from the inventive concept, and right is herein reserved to all such modifications falling within the scope 15 of the claim appended hereto.

What I claim is: i In an artificial leg, the combination with a hollow leg shank, of a foot and ankle assembly including an ankle block having an upper end secured in the lower end of said shank, a foot block below and spaced from the ankle block, a cushion member interposed between said blocks and extending to the edges thereof, an articulated connection between said blocks comprising an eyebolt secured in said ankle block centrally thereof and having a lower end extending into said cushioning member, a yoke secured to the top of the foot block and having a bifurcated part extending into the cushion member and straddling the lower end of said bolt, and means pivotally connecting said end of the bolt and bifurcated yoke part including a pintle, and a roller bearing as- 15 sembly in the eye-bolt surrounding said pintle.

GILBERT E. BECK. 

